This invention relates to endless belt conveyors as applied to agricultural machines such as large round balers and more particularly, to an improved roller for a conveyor having a plurality of side-by-side endless belts.
Conveyors in which a plurality of side-by-side flat belts are trained around a series of cylindrical rollers, one or more of which is driven so as to drive the belt through friction between the belt and roller, are well known, particularly as used in machines for forming large cylindrical bales of crop material. Such conveyor is described in U.S. Pat. No. 3,931,702 also assigned to the assignee of the present invention. As is also known it is often difficult to control the tracking of such belts which may not remain spaced on the rollers, but run to one side or the other, interfering with neighboring belts or parts of the machine, causing wear and damage to the belts and possibly interfering with the function of the conveyor.
A variety of fixed guides have been used to help control the tracking of the belts on the rollers. Typically, these are fixed rods attached to the frame of the machine, sometimes in the form of a rectangular loop straddling the belt. Disadvantages of such fixed guides are the possibility of a high wear rate on the belts from friction with the guide and also their tendency to cause troublesome buildups of crop material which readily "hairpins" around the rods.
In the past, multiple side-by-side flat belt conveyors have not been used in the lower generally horizontal conveyor of large round balers. In such an application, where typically the conveyor is short and subject to very uneven and heavy loading, control of belt tracking is particularly difficult. Conventional guides cannot be used on the upper conveying run of the belts where they would be most effective in controlling tracking because they would interfere with the conveying function. Applied to the lower return run of the conveyor they are relatively ineffective in controlling tracking and very prone to collecting trash.